Devices forming endoluminal intracorporeal endoprostheses are well known to the person skilled in the art, in particular for treating stenoses and above all aneurysms, in particular aneurysms of the abdominal aorta with extension to the femoral arteries in the zone where the femoral arteries branch apart.
For example, document WO 97/33532 contains a very complete description of a device forming an endoluminal prosthesis and the corresponding surgical or therapeutic method, the device comprising a body forming a common trunk and a first limb of great length that penetrates a sufficient distance into the femoral artery, and comprising a small second opening for connection of a second endoluminal endoprosthesis of corresponding small diameter that is designed to penetrate into the second femoral artery.
Such a device presents the following major drawbacks:
a) Because of the small diameter of the opening for connecting the second endoprosthesis to the first endoprosthesis, it is difficult to make this connection because it takes place in a zone suffering from aneurysm where it is easy to insert the second endoprosthesis outside the first endoprosthesis within the aneurysm, such that the practitioner has enormous difficulty in inserting the second endoprosthesis in the opening in the common trunk of the first endoprosthesis. PA1 b) Because the first endoprosthesis necessarily has a first limb incorporated in the device, such a prosthesis can be used only in highly specific clinical circumstances, given the physical conformation of the patient. It is necessary to make several types of endoprosthesis to match the physiological conformations of various patients, and some patients still do not correspond to any endoprosthesis and therefore cannot be treated by this method. PA1 c) Because of the presence of the first limb, the practitioner is obliged to use only one of the two femoral arteries for inserting the endoprosthesis device, and if it is calcified, the operation can no longer be performed. PA1 a) providing an endoluminal endoprosthesis-forming device of the invention as defined above; and PA1 b) inserting said endoluminal endoprosthesis-forming device in a blood vessel to be treated, in particular to avoid problems associated with aneurysm or stenosis.
The Applicant has also made a first invention concerning an endoprosthesis device and described in document FR-A-2 747 912, however it too is incapable of solving those drawbacks.
Likewise, document EP-A-0 783 873 describes a similar endoprosthesis that suffers from the additional drawback of requiring blood flow to be interrupted while it is being put into place, as shown in particular in its FIGS. 24 to 27.
In addition, the endoprosthesis-forming device in the form of a bifurcated stent as described in document EP-A-0 783 873 comprises at least one frustoconically shaped portion for joining to a stent or limb and that suffers from the drawback of creating stenoses.
With reference to its FIGS. 1A and 5, document EP-A-0 783 874 also describes an endoprosthesis-forming device comprising a first segment terminating in two limb starters of frustoconical shape opening out through smaller diameters and in which limb-shaped endoprosthesis-forming devices are positioned that have upstream ends terminating in appropriate frustoconical shapes, as can clearly be seen in FIGS. 6 and 7. That structure suffers from the major drawback due to the fact that positioning the second limb-shaped endoprosthesis device externally is unreliable since there is a risk of it becoming disconnected, in particular under the effect of blood flow. In addition, with that device, installation requires blood flow to be interrupted, as shown clearly in FIGS. 11 to 16.
In addition, as clearly shown in FIGS. 10 to 14, that endoprosthesis needs to have its downstream portion fixed on the low portion of the artery in a healthy region away from the aneurysm.
Document WO 97/40779 discloses a luminal endoprosthesis-forming device for ramification of a duct in the human or animal body comprising a tubular trunk element defining a cavity which is subdivided into a plurality of axial channels over at least a fraction of its length, this being done by inserting a sleeve of flexible biocompatible material into the cavity which is impermeable to body fluids, thereby forming a cavity which is useful for blood flow, and also forming the channels.
In practice, it is necessary to add another tubular trunk element referred to as a "prop" in order to prevent the sleeve of flexible biocompatible material collapsing inside the cavity it defines.
Under such conditions, that prior luminal endoprosthesis requires three distinct elements to be combined in order to achieve proper operation, and that greatly increases the complication of the procedure and the cost of such a device.
Also, and fundamentally, the tubular trunk element is outside the sleeve of flexible material defining the cavity and the channels, such that there is no limit on expansion, so it will deform to match the shape of the aneurysm.
As a result, during X-ray or scanner inspection, the endoprosthesis will take up the shape of the aneurysm and that will not lead to thrombosis of the aneurysm, so in practice no satisfactory treatment of the aneurysm can take place (see FIGS. 2 to 8 of that document, in particular).